Blyth RFC entertained Morpeth for the first time ever in the league with the visitors having been relegated last year from the North East leagues.
Blyth started well and it was no surprise when the ball was whipped along the line for powerful winger McKowen to barge over in the corner for an unconverted try.
Morpeth hit back were awarded a penalty for offside at the ruck, which was converted to bring the score to 5-3.
A period of intense pressure from the visitors resulted in Blyth defending no fewer than four five-metre scrums before finally clearing their lines.
Blyth then lost their winger with a shoulder injury and Karl Rose to the sin bin for what the referee deemed to be a technical offence.
More Morpeth pressure resulted in a drive from the lineout and an excellent move allowed the centre to score between the posts to make it 10-5 to the visitors at the interval.
Virtually from the restart Morpeth increased their lead with another converted try.
Blyth then suffered a massive blow with injuries forcing Bostock and Raine to leave the field.
In addition the home centre Bradwell was also injured but elected to stay on as there were no replacements left.
This left Blyth with a mountain to climb being forced to utilise two forwards in the backs and a hooker at wing-forward.
Morpeth took advantage and their threequarters combined to break through the depleted home defence for their third try, which effectively sealed the points.
Blyth fought back and captain Martin Stephenson was driven over for a try.
The injury hit Blyth side created a period of pressure in the last few minutes but a break away try gave Morpeth a four-try bonus point as the game ended 29-10 to the visitors.
On Saturday Blyth are away to Novos with a 3pm kick-off.